The invention relates to a disk brake, in particular a part-lining disk brake, having an electromechanical actuator and an application device of self-energizing type, which has a wedge arrangement designed to press a brake lining against a disk brake.
A self-energizing disk brake with a wedge arrangement is disclosed by German patent document DE 1 291 951, for example. This document describes a hydraulically actuated part-lining disk brake having a brake caliper or frame gripping around the brake disk, and an application device, actuated by a Bowden cable independently of the hydraulic actuation device, for application as a parking brake.
Wedge-shaped plates, which can be displaced against one another with their wedge faces bearing against one another, are arranged between the brake piston and the brake shoe or the brake lining, the plate facing the brake piston being braced against the brake cylinder or the brake caliper/frame. The plate acted upon by the brake piston in this example has pyramidal shape, preferably that of a truncated pyramid, counter-sliding wedges interacting with one pair of inclined faces for the mechanical brake actuation and counter-sliding wedges interacting with the other pair of inclined faces for adjustment of the brake clearance.
A disadvantage to this disk brake is the poor adjustability. It is therefore advisable to use an electric motor as actuator, which has the advantage of a good facility for adjustment and control. The adjustment can be computed in widely varying ways, where necessary incorporating a braking sensor or default variables.
Such an arrangement would still have the disadvantage, however, that it would have a relatively complicated construction. The embodiments of the invention eliminate this problem.
According to the invention, a disk brake is provided, in particular a part-lining disk brake, having an electromechanical actuator and an application device of self-energizing type, which as self-energizing device has a wedge arrangement designed to press a brake lining against a disk brake. At least two wedge elements moveable relative to one another are arranged on a brake caliper or frame or on an auxiliary frame for applying the application-side [brake lining], the elements being designed to act on the brake lining via a trapezoidal pressure plate, such as a wedge plate.
In an especially preferred embodiment of this arrangement, a unit which includes the wedge elements and the brake lining unit bearing against the brake disk can, during braking sequences, be moved together on the brake caliper or on the auxiliary frame parallel to the brake disk friction face against stops, against which it is braced during braking sequences.
Such bracing of the application forces against the brake caliper can advantageously be achieved, in this exemplary embodiment, without placing any stress on the actuator. The arrangement is suitable for braking both in a forward and in a reverse direction and in particular also for applications of a parking brake, even on ferries, where the inclination of the vehicle may change continuously. The brake moreover has a fundamentally simple design construction.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.